net/ipv4/ip_vti.c

   1 /*
   2  *      Linux NET3: IP/IP protocol decoder modified to support
   3  *                  virtual tunnel interface
   4  *
   5  *      Authors:
   6  *              Saurabh Mohan (saurabh.mohan@vyatta.com) 05/07/2012
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  *
  13  */
  14
  15 /*
  16    This version of net/ipv4/ip_vti.c is cloned of net/ipv4/ipip.c
  17
  18    For comments look at net/ipv4/ip_gre.c --ANK
  19  */
  20
  21
  22 #include <linux/capability.h>
  23 #include <linux/module.h>
  24 #include <linux/types.h>
  25 #include <linux/kernel.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/skbuff.h>
  28 #include <linux/netdevice.h>
  29 #include <linux/in.h>
  30 #include <linux/tcp.h>
  31 #include <linux/udp.h>
  32 #include <linux/if_arp.h>
  33 #include <linux/init.h>
  34 #include <linux/netfilter_ipv4.h>
  35 #include <linux/if_ether.h>
  36 #include <linux/icmpv6.h>
  37
  38 #include <net/sock.h>
  39 #include <net/ip.h>
  40 #include <net/icmp.h>
  41 #include <net/ip_tunnels.h>
  42 #include <net/inet_ecn.h>
  43 #include <net/xfrm.h>
  44 #include <net/net_namespace.h>
  45 #include <net/netns/generic.h>
  46
  47 static struct rtnl_link_ops vti_link_ops __read_mostly;
  48
  49 static unsigned int vti_net_id __read_mostly;
  50 static int vti_tunnel_init(struct net_device *dev);
  51
  52 static int vti_input(struct sk_buff *skb, int nexthdr, __be32 spi,
  53                      int encap_type)
  54 {
  55         struct ip_tunnel *tunnel;
  56         const struct iphdr *iph = ip_hdr(skb);
  57         struct net *net = dev_net(skb->dev);
  58         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
  59
  60         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
  61                                   iph->saddr, iph->daddr, 0);
  62         if (tunnel) {
  63                 if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
  64                         goto drop;
  65
  66                 XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4 = tunnel;
  67
  68                 return xfrm_input(skb, nexthdr, spi, encap_type);
  69         }
  70
  71         return -EINVAL;
  72 drop:
  73         kfree_skb(skb);
  74         return 0;
  75 }
  76
  77 static int vti_rcv(struct sk_buff *skb)
  78 {
  79         XFRM_SPI_SKB_CB(skb)->family = AF_INET;
  80         XFRM_SPI_SKB_CB(skb)->daddroff = offsetof(struct iphdr, daddr);
  81
  82         return vti_input(skb, ip_hdr(skb)->protocol, 0, 0);
  83 }
  84
  85 static int vti_rcv_cb(struct sk_buff *skb, int err)
  86 {
  87         unsigned short family;
  88         struct net_device *dev;
  89         struct pcpu_sw_netstats *tstats;
  90         struct xfrm_state *x;
  91         struct xfrm_mode *inner_mode;
  92         struct ip_tunnel *tunnel = XFRM_TUNNEL_SKB_CB(skb)->tunnel.ip4;
  93         u32 orig_mark = skb->mark;
  94         int ret;
  95
  96         if (!tunnel)
  97                 return 1;
  98
  99         dev = tunnel->dev;
 100
 101         if (err) {
 102                 dev->stats.rx_errors++;
 103                 dev->stats.rx_dropped++;
 104
 105                 return 0;
 106         }
 107
 108         x = xfrm_input_state(skb);
 109
 110         inner_mode = x->inner_mode;
 111
 112         if (x->sel.family == AF_UNSPEC) {
 113                 inner_mode = xfrm_ip2inner_mode(x, XFRM_MODE_SKB_CB(skb)->protocol);
 114                 if (inner_mode == NULL) {
 115                         XFRM_INC_STATS(dev_net(skb->dev),
 116                                        LINUX_MIB_XFRMINSTATEMODEERROR);
 117                         return -EINVAL;
 118                 }
 119         }
 120
 121         family = inner_mode->afinfo->family;
 122
 123         skb->mark = be32_to_cpu(tunnel->parms.i_key);
 124         ret = xfrm_policy_check(NULL, XFRM_POLICY_IN, skb, family);
 125         skb->mark = orig_mark;
 126
 127         if (!ret)
 128                 return -EPERM;
 129
 130         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(skb->dev)));
 131         skb->dev = dev;
 132
 133         tstats = this_cpu_ptr(dev->tstats);
 134
 135         u64_stats_update_begin(&tstats->syncp);
 136         tstats->rx_packets++;
 137         tstats->rx_bytes += skb->len;
 138         u64_stats_update_end(&tstats->syncp);
 139
 140         return 0;
 141 }
 142
 143 static bool vti_state_check(const struct xfrm_state *x, __be32 dst, __be32 src)
 144 {
 145         xfrm_address_t *daddr = (xfrm_address_t *)&dst;
 146         xfrm_address_t *saddr = (xfrm_address_t *)&src;
 147
 148         /* if there is no transform then this tunnel is not functional.
 149          * Or if the xfrm is not mode tunnel.
 150          */
 151         if (!x || x->props.mode != XFRM_MODE_TUNNEL ||
 152             x->props.family != AF_INET)
 153                 return false;
 154
 155         if (!dst)
 156                 return xfrm_addr_equal(saddr, &x->props.saddr, AF_INET);
 157
 158         if (!xfrm_state_addr_check(x, daddr, saddr, AF_INET))
 159                 return false;
 160
 161         return true;
 162 }
 163
 164 static netdev_tx_t vti_xmit(struct sk_buff *skb, struct net_device *dev,
 165                             struct flowi *fl)
 166 {
 167         struct ip_tunnel *tunnel = netdev_priv(dev);
 168         struct ip_tunnel_parm *parms = &tunnel->parms;
 169         struct dst_entry *dst = skb_dst(skb);
 170         struct net_device *tdev;        /* Device to other host */
 171         int pkt_len = skb->len;
 172         int err;
 173         int mtu;
 174
 175         if (!dst) {
 176                 dev->stats.tx_carrier_errors++;
 177                 goto tx_error_icmp;
 178         }
 179
 180         dst_hold(dst);
 181         dst = xfrm_lookup(tunnel->net, dst, fl, NULL, 0);
 182         if (IS_ERR(dst)) {
 183                 dev->stats.tx_carrier_errors++;
 184                 goto tx_error_icmp;
 185         }
 186
 187         if (!vti_state_check(dst->xfrm, parms->iph.daddr, parms->iph.saddr)) {
 188                 dev->stats.tx_carrier_errors++;
 189                 dst_release(dst);
 190                 goto tx_error_icmp;
 191         }
 192
 193         tdev = dst->dev;
 194
 195         if (tdev == dev) {
 196                 dst_release(dst);
 197                 dev->stats.collisions++;
 198                 goto tx_error;
 199         }
 200
 201         if (tunnel->err_count > 0) {
 202                 if (time_before(jiffies,
 203                                 tunnel->err_time + IPTUNNEL_ERR_TIMEO)) {
 204                         tunnel->err_count--;
 205                         dst_link_failure(skb);
 206                 } else
 207                         tunnel->err_count = 0;
 208         }
 209
 210         mtu = dst_mtu(dst);
 211         if (skb->len > mtu) {
 212                 skb_dst(skb)->ops->update_pmtu(skb_dst(skb), NULL, skb, mtu);
 213                 if (skb->protocol == htons(ETH_P_IP)) {
 214                         icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
 215                                   htonl(mtu));
 216                 } else {
 217                         if (mtu < IPV6_MIN_MTU)
 218                                 mtu = IPV6_MIN_MTU;
 219
 220                         icmpv6_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
 221                 }
 222
 223                 dst_release(dst);
 224                 goto tx_error;
 225         }
 226
 227         skb_scrub_packet(skb, !net_eq(tunnel->net, dev_net(dev)));
 228         skb_dst_set(skb, dst);
 229         skb->dev = skb_dst(skb)->dev;
 230
 231         err = dst_output(tunnel->net, skb->sk, skb);
 232         if (net_xmit_eval(err) == 0)
 233                 err = pkt_len;
 234         iptunnel_xmit_stats(dev, err);
 235         return NETDEV_TX_OK;
 236
 237 tx_error_icmp:
 238         dst_link_failure(skb);
 239 tx_error:
 240         dev->stats.tx_errors++;
 241         kfree_skb(skb);
 242         return NETDEV_TX_OK;
 243 }
 244
 245 /* This function assumes it is being called from dev_queue_xmit()
 246  * and that skb is filled properly by that function.
 247  */
 248 static netdev_tx_t vti_tunnel_xmit(struct sk_buff *skb, struct net_device *dev)
 249 {
 250         struct ip_tunnel *tunnel = netdev_priv(dev);
 251         struct flowi fl;
 252
 253         memset(&fl, 0, sizeof(fl));
 254
 255         switch (skb->protocol) {
 256         case htons(ETH_P_IP):
 257                 xfrm_decode_session(skb, &fl, AF_INET);
 258                 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
 259                 break;
 260         case htons(ETH_P_IPV6):
 261                 xfrm_decode_session(skb, &fl, AF_INET6);
 262                 memset(IP6CB(skb), 0, sizeof(*IP6CB(skb)));
 263                 break;
 264         default:
 265                 dev->stats.tx_errors++;
 266                 dev_kfree_skb(skb);
 267                 return NETDEV_TX_OK;
 268         }
 269
 270         /* override mark with tunnel output key */
 271         fl.flowi_mark = be32_to_cpu(tunnel->parms.o_key);
 272
 273         return vti_xmit(skb, dev, &fl);
 274 }
 275
 276 static int vti4_err(struct sk_buff *skb, u32 info)
 277 {
 278         __be32 spi;
 279         __u32 mark;
 280         struct xfrm_state *x;
 281         struct ip_tunnel *tunnel;
 282         struct ip_esp_hdr *esph;
 283         struct ip_auth_hdr *ah ;
 284         struct ip_comp_hdr *ipch;
 285         struct net *net = dev_net(skb->dev);
 286         const struct iphdr *iph = (const struct iphdr *)skb->data;
 287         int protocol = iph->protocol;
 288         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
 289
 290         tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex, TUNNEL_NO_KEY,
 291                                   iph->daddr, iph->saddr, 0);
 292         if (!tunnel)
 293                 return -1;
 294
 295         mark = be32_to_cpu(tunnel->parms.o_key);
 296
 297         switch (protocol) {
 298         case IPPROTO_ESP:
 299                 esph = (struct ip_esp_hdr *)(skb->data+(iph->ihl<<2));
 300                 spi = esph->spi;
 301                 break;
 302         case IPPROTO_AH:
 303                 ah = (struct ip_auth_hdr *)(skb->data+(iph->ihl<<2));
 304                 spi = ah->spi;
 305                 break;
 306         case IPPROTO_COMP:
 307                 ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
 308                 spi = htonl(ntohs(ipch->cpi));
 309                 break;
 310         default:
 311                 return 0;
 312         }
 313
 314         switch (icmp_hdr(skb)->type) {
 315         case ICMP_DEST_UNREACH:
 316                 if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
 317                         return 0;
 318         case ICMP_REDIRECT:
 319                 break;
 320         default:
 321                 return 0;
 322         }
 323
 324         x = xfrm_state_lookup(net, mark, (const xfrm_address_t *)&iph->daddr,
 325                               spi, protocol, AF_INET);
 326         if (!x)
 327                 return 0;
 328
 329         if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
 330                 ipv4_update_pmtu(skb, net, info, 0, 0, protocol, 0);
 331         else
 332                 ipv4_redirect(skb, net, 0, 0, protocol, 0);
 333         xfrm_state_put(x);
 334
 335         return 0;
 336 }
 337
 338 static int
 339 vti_tunnel_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 340 {
 341         int err = 0;
 342         struct ip_tunnel_parm p;
 343
 344         if (copy_from_user(&p, ifr->ifr_ifru.ifru_data, sizeof(p)))
 345                 return -EFAULT;
 346
 347         if (cmd == SIOCADDTUNNEL || cmd == SIOCCHGTUNNEL) {
 348                 if (p.iph.version != 4 || p.iph.protocol != IPPROTO_IPIP ||
 349                     p.iph.ihl != 5)
 350                         return -EINVAL;
 351         }
 352
 353         if (!(p.i_flags & GRE_KEY))
 354                 p.i_key = 0;
 355         if (!(p.o_flags & GRE_KEY))
 356                 p.o_key = 0;
 357
 358         p.i_flags = VTI_ISVTI;
 359
 360         err = ip_tunnel_ioctl(dev, &p, cmd);
 361         if (err)
 362                 return err;
 363
 364         if (cmd != SIOCDELTUNNEL) {
 365                 p.i_flags |= GRE_KEY;
 366                 p.o_flags |= GRE_KEY;
 367         }
 368
 369         if (copy_to_user(ifr->ifr_ifru.ifru_data, &p, sizeof(p)))
 370                 return -EFAULT;
 371         return 0;
 372 }
 373
 374 static const struct net_device_ops vti_netdev_ops = {
 375         .ndo_init       = vti_tunnel_init,
 376         .ndo_uninit     = ip_tunnel_uninit,
 377         .ndo_start_xmit = vti_tunnel_xmit,
 378         .ndo_do_ioctl   = vti_tunnel_ioctl,
 379         .ndo_change_mtu = ip_tunnel_change_mtu,
 380         .ndo_get_stats64 = ip_tunnel_get_stats64,
 381         .ndo_get_iflink = ip_tunnel_get_iflink,
 382 };
 383
 384 static void vti_tunnel_setup(struct net_device *dev)
 385 {
 386         dev->netdev_ops         = &vti_netdev_ops;
 387         dev->type               = ARPHRD_TUNNEL;
 388         ip_tunnel_setup(dev, vti_net_id);
 389 }
 390
 391 static int vti_tunnel_init(struct net_device *dev)
 392 {
 393         struct ip_tunnel *tunnel = netdev_priv(dev);
 394         struct iphdr *iph = &tunnel->parms.iph;
 395
 396         memcpy(dev->dev_addr, &iph->saddr, 4);
 397         memcpy(dev->broadcast, &iph->daddr, 4);
 398
 399         dev->hard_header_len    = LL_MAX_HEADER + sizeof(struct iphdr);
 400         dev->mtu                = ETH_DATA_LEN;
 401         dev->flags              = IFF_NOARP;
 402         dev->addr_len           = 4;
 403         dev->features           |= NETIF_F_LLTX;
 404         netif_keep_dst(dev);
 405
 406         return ip_tunnel_init(dev);
 407 }
 408
 409 static void __net_init vti_fb_tunnel_init(struct net_device *dev)
 410 {
 411         struct ip_tunnel *tunnel = netdev_priv(dev);
 412         struct iphdr *iph = &tunnel->parms.iph;
 413
 414         iph->version            = 4;
 415         iph->protocol           = IPPROTO_IPIP;
 416         iph->ihl                = 5;
 417 }
 418
 419 static struct xfrm4_protocol vti_esp4_protocol __read_mostly = {
 420         .handler        =       vti_rcv,
 421         .input_handler  =       vti_input,
 422         .cb_handler     =       vti_rcv_cb,
 423         .err_handler    =       vti4_err,
 424         .priority       =       100,
 425 };
 426
 427 static struct xfrm4_protocol vti_ah4_protocol __read_mostly = {
 428         .handler        =       vti_rcv,
 429         .input_handler  =       vti_input,
 430         .cb_handler     =       vti_rcv_cb,
 431         .err_handler    =       vti4_err,
 432         .priority       =       100,
 433 };
 434
 435 static struct xfrm4_protocol vti_ipcomp4_protocol __read_mostly = {
 436         .handler        =       vti_rcv,
 437         .input_handler  =       vti_input,
 438         .cb_handler     =       vti_rcv_cb,
 439         .err_handler    =       vti4_err,
 440         .priority       =       100,
 441 };
 442
 443 static int __net_init vti_init_net(struct net *net)
 444 {
 445         int err;
 446         struct ip_tunnel_net *itn;
 447
 448         err = ip_tunnel_init_net(net, vti_net_id, &vti_link_ops, "ip_vti0");
 449         if (err)
 450                 return err;
 451         itn = net_generic(net, vti_net_id);
 452         vti_fb_tunnel_init(itn->fb_tunnel_dev);
 453         return 0;
 454 }
 455
 456 static void __net_exit vti_exit_net(struct net *net)
 457 {
 458         struct ip_tunnel_net *itn = net_generic(net, vti_net_id);
 459         ip_tunnel_delete_net(itn, &vti_link_ops);
 460 }
 461
 462 static struct pernet_operations vti_net_ops = {
 463         .init = vti_init_net,
 464         .exit = vti_exit_net,
 465         .id   = &vti_net_id,
 466         .size = sizeof(struct ip_tunnel_net),
 467 };
 468
 469 static int vti_tunnel_validate(struct nlattr *tb[], struct nlattr *data[],
 470                                struct netlink_ext_ack *extack)
 471 {
 472         return 0;
 473 }
 474
 475 static void vti_netlink_parms(struct nlattr *data[],
 476                               struct ip_tunnel_parm *parms,
 477                               __u32 *fwmark)
 478 {
 479         memset(parms, 0, sizeof(*parms));
 480
 481         parms->iph.protocol = IPPROTO_IPIP;
 482
 483         if (!data)
 484                 return;
 485
 486         parms->i_flags = VTI_ISVTI;
 487
 488         if (data[IFLA_VTI_LINK])
 489                 parms->link = nla_get_u32(data[IFLA_VTI_LINK]);
 490
 491         if (data[IFLA_VTI_IKEY])
 492                 parms->i_key = nla_get_be32(data[IFLA_VTI_IKEY]);
 493
 494         if (data[IFLA_VTI_OKEY])
 495                 parms->o_key = nla_get_be32(data[IFLA_VTI_OKEY]);
 496
 497         if (data[IFLA_VTI_LOCAL])
 498                 parms->iph.saddr = nla_get_in_addr(data[IFLA_VTI_LOCAL]);
 499
 500         if (data[IFLA_VTI_REMOTE])
 501                 parms->iph.daddr = nla_get_in_addr(data[IFLA_VTI_REMOTE]);
 502
 503         if (data[IFLA_VTI_FWMARK])
 504                 *fwmark = nla_get_u32(data[IFLA_VTI_FWMARK]);
 505 }
 506
 507 static int vti_newlink(struct net *src_net, struct net_device *dev,
 508                        struct nlattr *tb[], struct nlattr *data[],
 509                        struct netlink_ext_ack *extack)
 510 {
 511         struct ip_tunnel_parm parms;
 512         __u32 fwmark = 0;
 513
 514         vti_netlink_parms(data, &parms, &fwmark);
 515         return ip_tunnel_newlink(dev, tb, &parms, fwmark);
 516 }
 517
 518 static int vti_changelink(struct net_device *dev, struct nlattr *tb[],
 519                           struct nlattr *data[],
 520                           struct netlink_ext_ack *extack)
 521 {
 522         struct ip_tunnel *t = netdev_priv(dev);
 523         __u32 fwmark = t->fwmark;
 524         struct ip_tunnel_parm p;
 525
 526         vti_netlink_parms(data, &p, &fwmark);
 527         return ip_tunnel_changelink(dev, tb, &p, fwmark);
 528 }
 529
 530 static size_t vti_get_size(const struct net_device *dev)
 531 {
 532         return
 533                 /* IFLA_VTI_LINK */
 534                 nla_total_size(4) +
 535                 /* IFLA_VTI_IKEY */
 536                 nla_total_size(4) +
 537                 /* IFLA_VTI_OKEY */
 538                 nla_total_size(4) +
 539                 /* IFLA_VTI_LOCAL */
 540                 nla_total_size(4) +
 541                 /* IFLA_VTI_REMOTE */
 542                 nla_total_size(4) +
 543                 /* IFLA_VTI_FWMARK */
 544                 nla_total_size(4) +
 545                 0;
 546 }
 547
 548 static int vti_fill_info(struct sk_buff *skb, const struct net_device *dev)
 549 {
 550         struct ip_tunnel *t = netdev_priv(dev);
 551         struct ip_tunnel_parm *p = &t->parms;
 552
 553         if (nla_put_u32(skb, IFLA_VTI_LINK, p->link) ||
 554             nla_put_be32(skb, IFLA_VTI_IKEY, p->i_key) ||
 555             nla_put_be32(skb, IFLA_VTI_OKEY, p->o_key) ||
 556             nla_put_in_addr(skb, IFLA_VTI_LOCAL, p->iph.saddr) ||
 557             nla_put_in_addr(skb, IFLA_VTI_REMOTE, p->iph.daddr) ||
 558             nla_put_u32(skb, IFLA_VTI_FWMARK, t->fwmark))
 559                 return -EMSGSIZE;
 560
 561         return 0;
 562 }
 563
 564 static const struct nla_policy vti_policy[IFLA_VTI_MAX + 1] = {
 565         [IFLA_VTI_LINK]         = { .type = NLA_U32 },
 566         [IFLA_VTI_IKEY]         = { .type = NLA_U32 },
 567         [IFLA_VTI_OKEY]         = { .type = NLA_U32 },
 568         [IFLA_VTI_LOCAL]        = { .len = FIELD_SIZEOF(struct iphdr, saddr) },
 569         [IFLA_VTI_REMOTE]       = { .len = FIELD_SIZEOF(struct iphdr, daddr) },
 570         [IFLA_VTI_FWMARK]       = { .type = NLA_U32 },
 571 };
 572
 573 static struct rtnl_link_ops vti_link_ops __read_mostly = {
 574         .kind           = "vti",
 575         .maxtype        = IFLA_VTI_MAX,
 576         .policy         = vti_policy,
 577         .priv_size      = sizeof(struct ip_tunnel),
 578         .setup          = vti_tunnel_setup,
 579         .validate       = vti_tunnel_validate,
 580         .newlink        = vti_newlink,
 581         .changelink     = vti_changelink,
 582         .dellink        = ip_tunnel_dellink,
 583         .get_size       = vti_get_size,
 584         .fill_info      = vti_fill_info,
 585         .get_link_net   = ip_tunnel_get_link_net,
 586 };
 587
 588 static bool is_vti_tunnel(const struct net_device *dev)
 589 {
 590         return dev->netdev_ops == &vti_netdev_ops;
 591 }
 592
 593 static int vti_device_event(struct notifier_block *unused,
 594                             unsigned long event, void *ptr)
 595 {
 596         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 597         struct ip_tunnel *tunnel = netdev_priv(dev);
 598
 599         if (!is_vti_tunnel(dev))
 600                 return NOTIFY_DONE;
 601
 602         switch (event) {
 603         case NETDEV_DOWN:
 604                 if (!net_eq(tunnel->net, dev_net(dev)))
 605                         xfrm_garbage_collect(tunnel->net);
 606                 break;
 607         }
 608         return NOTIFY_DONE;
 609 }
 610
 611 static struct notifier_block vti_notifier_block __read_mostly = {
 612         .notifier_call = vti_device_event,
 613 };
 614
 615 static int __init vti_init(void)
 616 {
 617         const char *msg;
 618         int err;
 619
 620         pr_info("IPv4 over IPsec tunneling driver\n");
 621
 622         register_netdevice_notifier(&vti_notifier_block);
 623
 624         msg = "tunnel device";
 625         err = register_pernet_device(&vti_net_ops);
 626         if (err < 0)
 627                 goto pernet_dev_failed;
 628
 629         msg = "tunnel protocols";
 630         err = xfrm4_protocol_register(&vti_esp4_protocol, IPPROTO_ESP);
 631         if (err < 0)
 632                 goto xfrm_proto_esp_failed;
 633         err = xfrm4_protocol_register(&vti_ah4_protocol, IPPROTO_AH);
 634         if (err < 0)
 635                 goto xfrm_proto_ah_failed;
 636         err = xfrm4_protocol_register(&vti_ipcomp4_protocol, IPPROTO_COMP);
 637         if (err < 0)
 638                 goto xfrm_proto_comp_failed;
 639
 640         msg = "netlink interface";
 641         err = rtnl_link_register(&vti_link_ops);
 642         if (err < 0)
 643                 goto rtnl_link_failed;
 644
 645         return err;
 646
 647 rtnl_link_failed:
 648         xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
 649 xfrm_proto_comp_failed:
 650         xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
 651 xfrm_proto_ah_failed:
 652         xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
 653 xfrm_proto_esp_failed:
 654         unregister_pernet_device(&vti_net_ops);
 655 pernet_dev_failed:
 656         unregister_netdevice_notifier(&vti_notifier_block);
 657         pr_err("vti init: failed to register %s\n", msg);
 658         return err;
 659 }
 660
 661 static void __exit vti_fini(void)
 662 {
 663         rtnl_link_unregister(&vti_link_ops);
 664         xfrm4_protocol_deregister(&vti_ipcomp4_protocol, IPPROTO_COMP);
 665         xfrm4_protocol_deregister(&vti_ah4_protocol, IPPROTO_AH);
 666         xfrm4_protocol_deregister(&vti_esp4_protocol, IPPROTO_ESP);
 667         unregister_pernet_device(&vti_net_ops);
 668         unregister_netdevice_notifier(&vti_notifier_block);
 669 }
 670
 671 module_init(vti_init);
 672 module_exit(vti_fini);
 673 MODULE_LICENSE("GPL");
 674 MODULE_ALIAS_RTNL_LINK("vti");
 675 MODULE_ALIAS_NETDEV("ip_vti0");